The River Clyde (Scottish Gaelic: Abhainn Chluaidh, pronounced [ˈavɪɲ ˈxl̪ˠuəj]) is a major river of western Scotland and the third-longest in the country at about 170 kilometres (110 mi) in length. Its river network extends to 4,244 km and drains a basin of 1,903 km2, expanding to 3,854 km2 when the Clyde estuary system with the Kelvin, White Cart, Black Cart and Leven is included. Around 1.79 million people, 33.8% of Scotland's population, live within this catchment. The river rises in the Lowther Hills and flows north-west through South Lanarkshire and Glasgow before entering the Firth of Clyde.
From the late 18th century the upper estuary and river through Glasgow were systematically engineered using groynes, longitudinal training walls and continuous dredging, and by removing rocky obstructions such as a large part of the Elderslie Rock. This was done to enable ocean-going access and support Glasgow's rise as a world centre of shipbuilding and marine engineering in the 19th and 20th centuries.
Since the later 20th century commercial deep-water functions have migrated down the estuary to naturally deep sites at Greenock, Finnart and Hunterston, while the upper river corridor has seen major regeneration in Glasgow. Environmental quality has improved from historic industrial lows, though legacy contaminants and periodic low-oxygen episodes in the outer firth have been reported.

Quelle: Wikipedia